Future liquid-argon DarkSide-20k and Argo detectors, designed for direct dark matter search, will be sensitive also to core-collapse supernova neutrinos, via coherent elastic neutrino-nucleus scattering. This interaction channel is flavor-insensitive with a high-cross section, enabling for a high-statistics neutrino detection with target masses of ∼50 t and ∼360 t for DarkSide-20k and Argo respectively. Thanks to the low-energy threshold of ∼0.5 keV nr achievable by exploiting the ionization channel, DarkSide-20k and Argo have the potential to discover supernova bursts throughout our galaxy and up to the Small Magellanic Cloud, respectively, assuming a 11-M progenitor star. We report also on the sensitivity to the neutronization burst, whose electron neutrino flux is suppressed by oscillations when detected via charged current and elastic scattering. Finally, the accuracies in the reconstruction of the average and total neutrino energy in the different phases of the supernova burst, as well as its time profile, are also discussed, taking into account the expected background and the detector response.

We report a study of the effect of postgrowth treatment of ZnGeP2 single crystals (low-temperature annealing, irradiation with fast electrons, polishing of working surfaces) and the conditions of exposure to repetitively pulsed laser radiation [wavelength (2091 or 1064 nm), pulse repetition rate, beam diameter, exposure time, sample temperature] on the laser-induced damage threshold (LIDT) of the surfaces of these crystals. It is found that thermal annealing of ZnGeP2 single crystals and their irradiation with a flux of fast electrons, which increase the LIDT at a wavelength of λ = 1064 nm, do not lead to a change in this threshold at λ = 2091 nm. It is shown that ZnGeP2 elements with lower optical losses in the spectral range 0.7 – 2.5 μm have a higher LIDT at λ = 2091 nm both immediately after fabrication and after postgrowth processing. An increase in the threshold energy density of laser radiation by a factor of 1.5 – 3 at λ = 2091 nm is revealed with a decrease in the crystal temperature from zero to –60 °C. The fact of reversible photodarkening of the propagation channel of laser radiation in ZnGeP2 in the predamage region of parameters is established by the method of digital holography.

Aria is a plant hosting a $${350}\,\hbox {m}$$ 350 m cryogenic isotopic distillation column, the tallest ever built, which is being installed in a mine shaft at Carbosulcis S.p.A., Nuraxi-Figus (SU), Italy. Aria is one of the pillars of the argon dark-matter search experimental program, lead by the Global Argon Dark Matter Collaboration. It was designed to reduce the isotopic abundance of $${^{39}\hbox {Ar}}$$ 39 Ar in argon extracted from underground sources, called Underground Argon (UAr), which is used for dark-matter searches. Indeed, $${^{39}\hbox {Ar}}$$ 39 Ar is a $$\beta $$ β -emitter of cosmogenic origin, whose activity poses background and pile-up concerns in the detectors. In this paper, we discuss the requirements, design, construction, tests, and projected performance of the plant for the isotopic cryogenic distillation of argon. We also present the successful results of the isotopic cryogenic distillation of nitrogen with a prototype plant.

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